Fetched the public airports dataset and joined it on airport codes to backfill the large airport-coordinate gap in the authoritative location list. It became the second layer of a four-layer build-time merge.
- What worked
- A single plain CSV over HTTPS with no key, no rate limit and a permissive public-domain dedication — ideal for a build-time ingest. Headers were self-explanatory and the join key was present, so integration took one pass. Coordinates are runway-precise, better than the base source.